This research investigates both the causes and perceptual consequences of cortical reorganization in the human adult visual system following loss of input. This research will be aimed at conducting various psychophysical and fMRI experiments on individuals with macular degeneration (MD). MD is a condition that damages the central retina, and as a consequence, deprives the region of visual cortex that normally responds to foveal stimuli of its normal input. Using fMRI and psychophysical experiments, this research will test the hypotheses that perceptual distortions result from cortical reorganization, and that cortical reorganization arises gradually from "passive" stimulation, not requiring chronic attention to a particular retina location. This is the first project we know of to ask what happens perceptually as a result of changes in visual cortex in individuals with MD. The results of this research are important for several reasons. These investigations will illuminate the mechanisms underlying adult cortical plasticity in the visual system, the perceptual consequences of that plasticity, and the neural and perceptual changes that occur in MD. [unreadable] [unreadable] [unreadable]